Bug 194566 - Create a randomized free list for new StructureIDs on StructureIDTable resize.
Summary: Create a randomized free list for new StructureIDs on StructureIDTable resize.
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Mark Lam
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2019-02-12 16:31 PST by Mark Lam
Modified: 2019-02-13 12:35 PST (History)
8 users (show)

See Also:

Attachments
proposed patch. (4.83 KB, patch)
2019-02-12 16:34 PST, Mark Lam 		no flags Details | Formatted Diff | Diff
proposed patch. (7.69 KB, patch)
2019-02-12 22:55 PST, Mark Lam 		msaboff: review+
Details | Formatted Diff | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Mark Lam 2019-02-12 16:31:19 PST 
<rdar://problem/47975502>
Comment 1 Mark Lam 2019-02-12 16:34:01 PST 
Created attachment 361863 [details]
proposed patch.
Comment 2 Saam Barati 2019-02-12 20:50:16 PST 
Comment on attachment 361863 [details]
proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=361863&action=review

> Source/JavaScriptCore/runtime/StructureIDTable.cpp:71
> +                table()[pick].offset = m_firstFreeOffset;

Why not just assign to zero?
Comment 3 Mark Lam 2019-02-12 20:52:09 PST 
Comment on attachment 361863 [details]
proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=361863&action=review

>> Source/JavaScriptCore/runtime/StructureIDTable.cpp:71
>> +                table()[pick].offset = m_firstFreeOffset;
> 
> Why not just assign to zero?

Oops.  This is a bug.  It should be:
    table()[pick].offset = head;
Comment 4 Mark Lam 2019-02-12 20:53:24 PST 
Looks like I should fix the 32-bit issues too.  Probably something trivial.
Comment 5 Mark Lam 2019-02-12 22:55:51 PST 
Created attachment 361899 [details]
proposed patch.
Comment 6 Michael Saboff 2019-02-13 10:35:30 PST 
Comment on attachment 361899 [details]
proposed patch.

r=me
Comment 7 Mark Lam 2019-02-13 12:33:23 PST 
Thanks for the review.  I re-tested the fixed patch with the CLI JetStream2, and perf appears to be neutral.  Will land now.
Comment 8 Mark Lam 2019-02-13 12:35:06 PST 
Landed in r241449: <http://trac.webkit.org/r241449>.